MANAGUA, Nicaragua -- For months, the reports percolated in Washington and other capitals. Iran was constructing a major beachhead in Nicaragua as part of a diplomatic push into Latin America, featuring huge investment deals, new embassies and even TV programming from the Islamic republic.

"The Iranians are building a huge embassy in Managua," Secretary of State Hillary Rodham Clinton warned in May. "And you can only imagine what that's for."

But here in Nicaragua, no one can find any super-embassy.

Nicaraguan reporters scoured the sprawling tropical city in search of the embassy construction site. Nothing. Nicaraguan Chamber of Commerce chief Ernesto Porta laughed and said: "It doesn't exist." Government officials say the U.S. Embassy complex is the only "mega-embassy" in Managua. A U.S. diplomat in Managua conceded: "There is no huge Iranian Embassy being built as far as we can tell."

The mysterious, unseen giant embassy underscores how Iran's expansion into Latin America may be less substantive than some in Washington fear.

Iran's proposed investments in Nicaragua -- for a deep-water port, hydroelectric plants and a tractor factory -- have also failed to materialize, Nicaraguan officials say. At a time when Iran's oil revenue is falling, the same is true of many projects planned for Latin America, according to analysts.

U.S. officials emphasized that there is plenty of reason to be concerned about Iran, which they consider a state sponsor of terrorism. But the Iranian activity has revived Cold War-style rhetoric in Washington that at times doesn't match what is evident in places such as Managua.

Last month, Rep. Connie Mack (R-Fla.) even told reporters in a call organized by the Israel Project that "the growing influence of Iran in the Western Hemisphere reminds me of the relationship between Russia and Cuba when we dealt with the Cuban missile crisis."

It is not clear where the report of the embassy in Managua began. But in the past two years, it has made its way into congressional testimony, think tank reports, press accounts, and diplomatic events in the United States and elsewhere.

"Iran recently established a huge embassy in Managua," Nancy Menges of the Center for Security Policy told a House committee last year. "Iran's embassy in Managua is now the largest diplomatic mission in the city," wrote Michael Rubin of the American Enterprise Institute.

State Department spokesman Philip J. Crowley said that Clinton heard about the embassy during a recent meeting in the region. "If it turns out this is not happening, that's good news," he said.

"It perhaps suggests the Iranians are talking about investments and influence that they don't yet have," he said. "But they are certainly feeling their oats, and they are certainly trying to exploit opportunities where they think they exist."